This invention relates generally to X-ray imaging systems, and more particularly, to X-ray detectors.
X-ray imaging systems use X-ray detectors to form an image of an object that is being scanned. X-ray detectors typically use a single sensing layer composed of a scintillator layer and a photodiode layer to form an image of the object. Both the layers are divided into a number of cells. The combination of a scintillator cell and a photodiode cell forms an X-ray detector cell. A number of such X-ray detector cells are combined to form the X-ray detector. When an X-ray falls on a scintillator cell, the scintillator cell emits visible light. The intensity of the emitted light is proportional to the intensity of the X-ray. The emitted light is directed towards a photodiode cell. The photodiode cell converts the light into an electrical signal. The amplitude of the electrical signal is proportional to the intensity of the light incident on the photodiode cell.
The resolution of an image obtained after scanning an object depends on the size of the X-ray detector cell, the complexity of the interconnect for these cells and the associated electronics. One technique to increase the resolution of scanned images is to reduce the size of the X-ray detector cells. However, the reduction in the size of the X-ray detector cells increases the cost and complexity of the X-ray imaging system.